Nerd’s Eye View: Inside Fredric Aasbo/Papadakis Racing’s Amazing V8 eating 2AR Toyota Engine


Unlike most modern high horsepower blocks, the 2AR does not feature a stud girdle, a deep skirt block or a bed plate for stiffness.  It does have help for stiffening though.
The thick and beefy upper pan assembly completely closes in the lower part of the block and contributes greatly to overall stiffness.  It also functions as a baffle scraper/windage tray to help speed oil return to the pan.
Most engines producing this sort of power need dry sumps to keep it all together.  The 2AR oiling system is so good, it works fine just stock even at over 800 hp and 30 psi of boost.  The perfect bearings are witness to that even in the high G load arena of drifting, the stock oil system is unfazed when most other engines need drysumps.  The oil pump pickup, oil pump and balance shafts are contained in this casting.  For this year the team has done as lot of suspension development and has relocated the steering rack for better geometry.  The problem is the rack goes right through the pan.  The pan had to be chopped and clearanced so that also means that the oil pump and balance shaft casting had to be chopped.  Fortunately the oil pump is in the front and the balance shafts are removed.
 Here is the pan with the cut out for rack clearance.
The team uses a big Borg Warner EFR 8374 turbo.  The high tech turbo features floating dual row ball bearings, a super light and fast spooling 74mm titanium aluminide turbine wheel and a 0.83 a/r investment cast stainless dual scroll exhaust housing.  The twin scroll really helps turbine efficiency and spools the turbo much faster.  The compressor wheel is an extended tip billet part with an 83mm exducer and a large 62.6 mm inducer.  It flows 79 lbs per min so it is close to being maxed out.  Borg Warner's turbo technology gives a responsiveness to a big turbo.  The boost comes in fast and at a low RPM.  Although it is hard to see, Brian Kono of Afterhours Automotive fabricated the tubular stainless exhaust header from 321 stainless.
Dual 38mm Tial wastegates control the boost.  Twin wastegates are used to keep the flow on each side of the twin scroll discrete.


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